This invention relates to a protector panel assembly for telecommunication connections for protecting against high voltages and surge currents, particularly for a protector panel assembly for use at high frequency telecommunications.
Telecommunication lines within, for example, a telephone system or data system should be protected from high voltages and surge currents that may occur on the lines. Such voltages and currents may damage telecommunications equipment to which the lines are coupled and pose a safety hazard to people using the equipment. Each telecommunication line is comprised of a twisted-pair of wires. For business uses, norm-ally,.each twisted-pair of wires-extends into a protector panel that is capable of handling a number of lines. The protector panel has a plurality of rows of sockets on a front side of the panel, each of the sockets having two pairs of receptacles for receiving pins of a plug-in excess voltage module. In the event of a high surge current or excessive voltage occurring, the module conducts to ground to protect equipment and personnel. Twisted pairs of wires leading from a telecommunications provider outside of the facility, referred to herein as xe2x80x9coutside-plantxe2x80x9d wires, connect to the protector panel assembly. Wires leading from the protector panel to the equipment within the customer premises are referred to herein as xe2x80x9ccustomer premisesxe2x80x9d wires.
Protector panels are constructed to occupy a minimal amount of space while serving a large number of twisted-pair lines. On the back side of the panel, a plurality of rows of pins protrude, each of the pins registering with one of the receptacles to provide a socket pattern with two pairs of pins for each socket. A ground bar extends between the pins on each row. A back portion of an outside plant connector block and a customer premises connector block are located on opposite sides of the rows of pins. The outside-plant connector block has a plurality of terminals that are electrically connected to wires of an outside plant cable, such as ones coming from a telephone company. The customer premises connector block also has terminals that are electrically connected to wires that are leading to the customer""s equipment. Jumper wires extend from a pair of pins of each socket pattern to the outside-plant connector block. Similarly, jumper wires extend from the other pair of pins of each of the socket patterns to the customer premises connector block.
The outside-plant cable comprises a bundle of twisted pair wires within an elastomeric sheath. The twisting is known to reduce cross-talk between wires. Cross talk is an unwanted signal coupling between two or more pairs of wires. Typically, cross talk occurs between wires that are physically close to one another. The strength of the interference or cross talk is directly proportional to the square of the distance. In some cable bundles, the amount of twist per inch, or pitch, varies among the twisted pairs, particularly among the twisted-pairs in the bundle that are in close proximity to each other. However, in the prior art, the jumper wires extending between the pins and the customer premises and outside-plant connector blocks are not twisted.
While this type of protector panel has been suitable in the past for voice communication, say 300Hz to 3.5 KHz, these panels are not acceptable in very high frequency applications. For digital communication, the frequency may be as high as 100 MHZ. Cross talk may occur with prior art panels at very high frequency, particularly if there are a number of wires crowded into limited space on the back of the protector panel.
The protector panel of this invention has a plurality of rows of sockets on a front side of the panel. Each of the sockets has two pairs of receptacles and a ground receptacle for receiving pins of a plug-in excess voltage module. A plurality of rows of pins protrude from a back side of the panel. Each of the pins registers with one of the receptacles to provide two pairs of pins for each socket pattern.
A pair of outside-plant wires extend from one of the pairs of pins of each socket pattern. Each of the pair of wires is twisted substantially along its entire length. The amount of twist of at least some of the pairs of outside-plant wires within each row differ from the amount of twist of at least some of the other pairs of outside-plant wires within the same row. Similarly, a twisted-pair of customer premises wires extend from the other pair of pins of each socket pattern. The amount of twist of at least some of the pairs of customer premises wires within each row differ from the amount of twist of at least some of the other pairs of customer premises wires within the same row. Furthermore, in the preferred embodiment, the pitches of the outside-plant and customer premises wires leading to pins of adjacent socket patterns in adjacent rows differs from one another. The difference in pitch between adjacent socket patterns in adjacent rows is preferably greater than the difference in pitch between socket patterns within the same row. The outside-plant and customer premises wires for each of the socket patterns extend away from each other, rather than overlying each other to further avoid cross talk.